Tied to the one SIM, the Data Share Package allows customers to spread their data usage on up to four devices, including laptops, smartphones or tablets.

The add on features are for Every Day Connect and Business Performance customers, simply adding $10 a month to add the Data Share Package to your plan, and another $10 for each additional SIM card for your devices.

This simply means that, for example, a $60 Every Day Connect plan will cost $70 a month to add the shared data package, and either another $10, $20 or $30 per month over 24 months if you want one, two or three extra SIMs, respectively.

Telstra is offering an extra 1GB of data for your monthly allowance if you sign up before 31 December 2013.

But if the data allowance on your chosen plan tier isn't enough, you could also add an additional data pack, but your monthly charge will go up.

Playing SIMs

Not all devices have slots for SIM cards, but for those that do, the Telstra's package could be a handy addition.

Of course, you could just use Wi-Fi or Bluetooth tethering to share data between devices without any extra charges, though this could hit both device's battery quite hard.

It should also be noted that the largest amount of data that Telstra offers on its Every Day Connect plans is 3GB, reserved for its highest tier.

Consumer advocacy group the Australian Communications Consumer Action Network (ACCAN) applauded Telstra for offering flexibility with the add-on, but also noted that it was still at a cost.

"The relatively high cost to use data sharing means the free tethering features built into devices are likely to be a sufficient alternative for some," Asher Moses, ACCAN spokesman, told Computerworld Australia.